This invention relates to hoppers particularly adapted to railway cars. In railway hopper cars there are provided gates for closing and opening the discharge outlet at the lower end of the hopper. Various types of gates or closures have been proposed and used to close off the discharge outlet. The primary difficulty has been in controlling seepage of product especially of particulate product such as alumina which is difficult to contain.
The present invention discloses a hopper with a bottom opening which is closed by a gate assembly having superposed upper and lower plates with their interfaces provided with cooperating wedges serving to lift the upper plate to closing position with the discharge opening against an encompassing sealing strip supported on a marginal edge portion of the hopper.